Specifying Architectural Push/Pulls
This article outlines the basic information you need to specify or order architectural pulls, push bars or push/pulls.
Push Bars and Straight or Offset Wire Door Pulls
- Center to Center (CTC) dimension
- Wire diameter
- Door thickness
- Mounting option
You may also need:
- Clearance and/or projection dimension
In addition, for offset door pulls:
- Size (distance from mounting center line) of offset
- Angle of offset
Door conditions, such as width, thickness, height and the presence of other hardware affect the CTC dimension. If a pull is being used as exit device exterior trim and there is a key cylinder involved, for example, the pull must allow access to the cylinder and be large enough to straddle the head of the exit device.
When sizing a push bar for an aluminum and glass storefront door, typically one subtracts the stile width from the door width to get the CTC dimension. For example, if you have a 36-inch aluminum and glass door with 3-inch stiles, you would specify a CTC dimension of 33 inches so that the ends of the pushbar would both fall exactly in the middle of each stile. However, if there is a lock on the door with an exterior pull and key cylinder, one might want to specify the CTC dimension so that the hinge end of the push bar would fall in the middle of the hinge stile, but the lock end of the push bar would fall in line with the backset of the lock. This may become more important in push/pull applications.
Manufacturers offer a wide variety of means to attach push/pull hardware to the door. There are decorative and not-so-decorative through-bolts, “cone head” fasteners for “blind” mounting, and back-to-back mounting options.
Through-bolts are commonly used for door pulls especially when there is no other hardware on the door, such as a concealed vertical rod exit device, that might interfere with through-bolt placement. Through-bolts are the strongest and simplest mounting method.
“Cone head” fasteners are bolts with a special cone-shaped head that has a groove milled into it to secure a set screw. Cone heads can be used when there is something in the way that prevents though-bolting or to accomplish back-to-back mounting as shown in the illustrations at right.
This article covers the basics of pull and push/pull specification. In addition, there are full height door pulls, designer door pulls, custom door pulls - the variety is endless. The most important thing to remember is to take good measurements and keep in mind all the hardware that is going to be on the door.